In the past, a battery has been widely used as a mean for supplying power to electric apparatuses. In the past, primary batteries such as a manganese battery, an alkaline manganese battery, and a zinc-air battery, and secondary batteries such as a nickel-cadmium battery, a nickel-hydrogen battery, and a lithium ion battery have been used as the battery. Among these batteries, the air-zinc battery supplies a relatively high voltage of 1.4 V and has advantages such as high energy density and large discharge capacity. In addition, since the air-zinc battery exhibits almost constant discharge characteristics until a discharge thereof is completed, it is considered that the air-zinc battery can replace a mercury battery, of which use is inhibited due to heavy metals contained in the mercury battery.
In order for the air-zinc battery to be applicable to electric appliances for various purposes such as household purposes, industrial purposes, and military purposes, the air-zinc battery is commonly manufactured in the form of an air-zinc battery module which includes minimum battery units, i.e., a plurality of air-zinc battery cells to meet required voltage and current specifications. Since the air-zinc battery module includes the plurality of air-zinc battery cells, a fan device is essentially required to uniformly supply air to all the air-zinc battery cells in the air-zinc battery module. In addition, electric wiring, a power supply, and a switching structure for supplying power to the fan are also important parts so as to miniaturize a battery module product and maximize a lifespan of the battery module product.
FIG. 1 illustrates an arrangement structure of a fan of an existing air-zinc battery module. According to an air-zinc battery module 10 of FIG. 1, two battery units 12 are connected in series in a case 11, and a fan 13 for guiding an air flow into the air-zinc battery module is located in an air inlet 14 of the case (i.e., is exposed to the outside). However, according to the arrangement structure of the fan 13, when external air is supplied to the battery units 12 in the air-zinc battery module, air is intensively supplied only to the battery unit 12 disposed adjacent to the air inlet 14, and air is not sufficiently supplied to the battery unit 12 located far away from the air inlet 14. As a result, an air supply bias or unbalance phenomenon between the battery units becomes a factor which significantly shortens an overall lifespan of the air-zinc battery module. In order to overcome such a problem, it is possible to consider using a fan having a stronger wind force. However, this have to face a problem in that power consumption is increased.
In addition, since the fan is exposed to the outside, a fan blade is contaminated to cause a reduction in an air flow rate, thereby reducing performance of a battery module and causing noise of the fan.
Furthermore, since the existing air-zinc battery module should include a separate heavy battery device for driving the fan, there is a limit in reducing weight of a battery module product and simplifying a structure thereof. Since the existing air-zinc battery module has a structure in which a separate switching device is required to control driving of the fan, space efficiency in the battery module is lowered. Thus, a product is difficult to miniaturize, the electric wiring is complicated, and manufacturing costs are increased. In addition, when the fan is not accidentally turned off at the time of controlling driving of the fan, a battery may be unnecessarily discharged to inadvertently reduce a lifespan of a battery module.